Stabilizers for fluid cylinder plungers



J. H. WILSON Dec. 3, 1968 STABILIZEHS FOR FLUID CYLINDER PLUNGERS 7Sheets-Sheet 1 Filed Feb. 13, 1967 Dec. 3, 1968 J. H. WILSON 3,413,767

STABILIZERS FOR FLUID CYLINDER PLUNGEHS Filed Feb. 13, 1967 7Sheets-Sheet 2 7 Sheets-Sheet I JOHN HART WILSON INVENTOR Ea HIS AGENT 4w m w J. H. WILSON Dec. 3, 1968 STABILIZERS FOR FLUID CYLINDER PLUNGERSFil'ed Feb. 13, 1967 Dec. 3, 1968 J. H. WILSON STABILIZERS FOR FLUIDCYLINDER PLUNGERS 7 Sheets-Sheet 4 Filed Feb. 13, 1967 5 f a I m M m H a2 O 9 "w 2 L c QW\\\\\\\ V Y\\\\\ \&\\\\ ,\\\\\\\\\\\\\\Nk- JOHN HARTWILSON INVENTOR.

MAG E N T Dec. 3, 1968 J. H. WILSON 3,413,767

STABILIZERS FOR FLUID CYLINDER PLUNGERS Filed Feb. 13, 1967 7Sheet-Sheet b 32 523 i w i Q 50 J S w Q JOHN HART WILSON IN VEN TOR.

Dec. 3, 1968 .1. H. WILSON 3,413,767

STABILIZERS FOR FLUID CYLINDER PLUNGERS Filed Feb. 1:5, 196? 7Sheets-Sheet 6 JOHN HART WILSON IN VEN TOR.

HIS AGENT Dec. 3, 1968 J. H. WILSON 3,413,767

STABILIZERS FOR FLUID CYLINDER PLUNGERS Filed Feb. 13, 1967 7Sheets-Sheet '7 JOHN HART WILSON IN VEN TOR.

3,413,767 STABILIZERS FOR FLUID CYLINDER PLUNGERS John Hart Wilson,%Wilson Mfg. Co., P.0. Box 1031, Wichita Falls, Tex. 76307Continuation-impart of application Ser. No. 410,700,

Nov. 12, 1964. This application Feb. 13, 1967, Ser.

6 Claims. (Cl. 52115) ABSTRACT OF THE DISCLOSURE A stabilizer forstabilizing plungers of fluid cylinders of high slenderness ratio, tosupport the plunger against lateral deflection within the lengththereof, when the plunger is used in towers, such as extensible masts,or in elavator shafts. The stabilizing device utilizes arms tosequentially move into engagement, at spaced intervals, with the plungeras the extensible mast or the elevator car moves upward, and to move outof engagement with the plunger and out of the path of the extensive mastor elevator car as the extensible mast or elevator car moves downward.The stabilizer arms are maintained in disengaged position while theextensible mast or the elevator car is moved therebelow.

This application is a continuation-in-part and co-pending withapplication Ser. No. 410,700, filed Nov. 12, 1964, and now abandoned forStabilizer for Fluid Cylinder Plungers Such as Used in Connection WithMasts and Extensible Towers.

This invention relates to improvements in a stabilizer for fluidcylinder plungers such as used in connection with masts, extensibletowers and other fluid cylinder plungers which may be extended to suchlength that are not stable against lateral movement.

Various stabilizers have been proposed heretofore such as disclosed inmy Patent No. 3,016,992 granted Jan. 16, 1962, for Stabilizer for FluidCylinder Plungers of High slenderness Ratio.

The present fluid cylinder plunger stabilizer is so constructed that aminimum of mechanism is required to operate the stabilizer, which isoperated automatically as the extensible inner portion of the mast ortower is moved upward or downward past a predetermined point, or theplunger is extended to an unstable height. While only one stabilizer isshown, as many as desired may be made to operate within the length ofthe outer mast structure or tower and stabilizer arms will move intoplace to stabilize the plunger of a cylinder as the inner mast portionmoves upward, and the stabilizer arms will move out of stabilizingposition as the inner portion of the mast or tower is lowered.

By having a mast or tower that is constructed with the inner mastportion thereof movable with respect to the outer mast structure andwith the inner portion being lifted by a hydraulic ram, the presentdevice will stabilize the plunger each time the lower end of the innermast portion passes a section of the outer mast structure, where astabilizer is mounted. In this manner a relatively slender plunger thatis of extreme length may be readily used where heretofore the extensionof such plunger was limited, if it was unstabil ized. Stabilizers may beso constructed as to stabilize a plurality of plungers arranged tooperate in parallel relation, and for stabilizing extended plungers suchas plungers for elevators using fluid cylinders.

An object of this invention is to provide a plunger stabilizer whichwill prevent an elongated plunger from moving laterally as it extendsoutward from a hydraulic ram such as is used for mast and tower sectionsand the like.

nited States Patent Still another object of the invention is to providea plunger stabilizing mechanism that will move into place and surroundthe plunger of a hydraulic cylinder, which is of high slenderness ratio,at spaced intervals along the length thereof as the plunger becomesexposed, so as to prevent lateral deflection of the exposed, extendedplunger.

Still another object of the invention is to provide a hydraulic plungergripping mechanism to grip and sta bilize a plunger, which mechanism issimple in construction, easy to apply to a mast or a tower, and whichoperates automatically, and which requires a minimum of attention andservice.

Yet another object of the invention is to provide a plunger withstabilizing arms for stabilizing plungers of high slenderness ratio,which stabilizer arms will move into place as the plunger of a hydrauliccylinder moved upward within a structure, to support the plunger againstlateral deflection, at spaced intervals along the length thereof.

A further object of the invention is to provide a plunger stabilizingmechanism to stabilize the plungers of fluid cylinders, as the plungersare extended, to maintain the plungers substantially in alignment withthe fluid cylinders, with the stabilizers being moved into engagedrelation with respect to the plunger sequentially, as the plunger movesoutward with respect to the fluid cylinder, so as to support the plungeragainst lateral deflection.

Yet a further object of the invention is to provide a plunger stabilizerfor stabilizing plungers of high slenderness ratio, such as used inhydraulic elevators in the elevator shafts of buildings, and the like,whereby the plunger stabilizers will be sequentially moved intosupporting relation with the plunger as the elevator car moves upwardwithin the elevator shaft, and which stabilizers will be sequentiallymoved into retracted position as the elevator car moves downward.

In the manufacture of portable masts or tower structures, it isdesirable to telescope the upper portion of the mast or tower into thelower portion thereof, so that the structure will be within acceptablelimits for movement over the highways, but which may be raised to anupright position and extended into operating position to present a mastor derrick of suflicient height to enable the handling of long lengthsof drill stem or pipe, so as to expedite the drilling an/or servicing ofdeep wells, such as oil wells or the like.

The present device is suitable for use on hydraulic cylinder plungers,such as used in hydraulic elevators of buildings \and the like. Thepresent plunger stabilizers enable plungers of high slenderness ratio tobe used in multi-story buildings, the height of which, heretofore, madeit impossible to stabilize plungers against lateral deflection,therefore, the use of hydraulic elevators, so far as known, has beenconfined to buildings of two to six stories, however, the use of thepresent device enables plungers to be used in buildings of twelve ormore stories, whereby the plungers will be maintained against lateraldeflection by the arms of the stabilizer.

Embodiments of the invention are illustrated in the accompanyingdrawings, in which like reference characters designate like parts in theseveral views thereof, in which:

FIG. 1 is a tl'lOI'lZOIItfll, transverse, sectional view taken throughthe mast structure, showing the arms of the stabilizer surrounding andsupporting the plunger, with the section being taken on the line 1-1 ofFIG. 2, looking in the direction indicated by the arrows;

FIG. 2 is a fragmentary front elevational view of an outer and innersection of a mast, showing the plunger stabilizer members surroundingand, being in gripping relation with a hydraulic cylinder plunger;

FIG. 3 is a fragmentary side view of the mast structure as shown in FIG.2, but with the plunger stabilizer shown in vertical, disengagedposition;

FIG. 4 is a view on reduced scale of a fragmentary portion of the innerportion of a mast, showing the plunger stabilizer in vertical,disengaged position;

FIG. 5 is a view showing a plunger stabilizer arm apart from the mast;

FIG. 6 is a longitudinal, sectional view taken through the shaft of anelevator, with parts broken away and shortened, showing an elevator car,a hydraulic cylinder plunger assembly associated therewith, and showinghydraulic cylinder plunger stabilizer arms in elevation within theelevator shaft;

FIG. 7 is a fragmentary, longitudinal view, on an enlarged scale, withportions broken away, with portions shortened, and with portions shownin elevation, with the plunger of the hydraulic cylinder stabilizer armsbeing shown in retracted position;

FIG. 8 is a view similar to FIG. 7, but showing hydraulic cylinderplunger stabilizer arms in outwardly extended position, and as beinginterengaged with the plunger of the hydraulic cylinder;

FIG. 9 is a sectional view taken on the line 9-9 of FIG. 8, looking inthe direction indicated by the arrows;

FIG. 10 is a further enlarged, fragmentary, perspective view of one ofthe hydraulic cylinder plunger stabilizer arms, shown apart from theelevator shaft, with parts broken away, with parts shown in section andparts shortened to bring out the details of construction;

FIG. 11 is a fragmentary side elevational view, on a scale similar toFIG. 10, with portions broken away, with portions shortened, and withportions shown in dashed outline, of the latch mechanism for holding thearms, including the arm, shown as holding the arm in retracted position;

FIG. 12 is a view similar to FIG. 11, but showing one of the arms forstabilizing the hydraulic cylinder plunger in an outwardly extendedposition; and

FIG. 13 is a fragmentary, perspective view, shown apart from theelevator car and elevator shaft, of the latch mechanism for holding aplunger stabilizer arm in retracted position and for releasing the arm.

With more detailed reference to the drawings, the numeral 1 designatesgenerally the outer mast structure which slidably receives an inner mastportion 2 therein. The inner mast portion has a hydraulic cylinderplunger 4 extending from the hydraulic cylinder (not shown) downward tothe base of the mast when the mast or tower is in upright position.

In the extending of relatively tall masts or towers by a hydraulic ram,as by sliding one section within another section, it is necessary tostabilize the plunger thereof to prevent the lateral movement of theplunger with respect to the normal axis thereof.

In the present invention the inner portion 2 of the mast or tower islongitudinally movable with respect to the outer mast structure 1 andthe plunger 4 is positioned mediate the sides of the outer maststructure, and is capable of being stabilized by a pair of arms orstabilizing frames 6, each of which arms or frames is mounted on a shaft8, which shafts are each journaled in bearings 10 on the opposite sidesof the outer mast structure. Each arm 6 is secure to the respectiveshafts 8 and rotatable therewith through an arc of approximately 90degrees. The shaft 8 has an outwardly extending lever 12 mounted thereonand secured thereto, each which lever is apertured and to which issecured an end of a tension spring or spring means 14 with the other endthereof being anchored to an apertured lug 16 on the respective outermast structure. Levers 12 are adapted to move through an arc of 90degrees from a position as shown in full outline in FIG. 2 to theposition as shown in dashed outline in FIG. 2.

Each of the arms 6 has a pair of upstanding lugs 18 thereon, which lugsare apertured to receive an axle of a roller 20 therein to mount theroller 20 in journaled relation thereon.

Upon raising the mast, as the mast moves upward the rollers 20 roll offof trackway 24 on to a cam 22, which is arcuate and which will permitthe arm 6 to move from the position as indicated in dashed outline inFIG. 2 to the position indicated in full outline in FIG. 2, upon actionof spring 14 to act upon lever 12 to rotate shaft 8 through an arcuatemovement of approximately 90 degrees.

The inner end portion of each arm 6 has an arcuate semi-cylindricalportion 7 secured thereon, which is preferably lined with paddingmaterial, such as woven belting, as indicated at 7a, so that thesemicylindrical portion 7 will blindly engage around the plunger 4 tohold the plunger against lateral movement. As the inner mast portion 2moves upward successive pairs of arms 6 will swing outward sosemi-cylindrical portions 7 will surround the plunger at spacedintervals to stabilize the plunger against lateral movement in anydirection.

Normally the arms extend outward in horizontal position as indicated inFIGS. 2 and 3 under the influence of spring 14 when not constrained toanother position by a cam 22 and trackway 24. When the inner mastportion 2 is telescoped into outer mast structure 1, the cam face 22.which is arcuate, engages the roller 20 as indicated in FIG. 2 and asthe inner mast portion 2 moves downward each of the cam faces 22 contactthe respective rollers 20 to move the arms 6 from the position shown infull outline in FIGS. 2 to the positions shown in dashed outline in FIG.2. As the inner mast portion moves downward the trackway 24 engages therollers 20 and holds the arms 6 in position as indicated in dashedoutline in FIG. 2. As the inner mast 2 moves by successive arm mountings6. each pair of arms is acted upon in a similar manner until the mast isin full telescoped position.

Modified form of invention Various hydraulically operated elevators havebeen proposed heretofore, but due to the deflection of the plunger of ahydraulic cylinder, it has been impractical to use such elevators,insofar as known, in buildings in excess of six stories in height. Thepresent stabilizer for the plungers of elevators is so constructed, thatsuch elevators may be operated in buildings of twelve or more stories inheight, with hydraulic cylinder utilizing a plunger of relatively smalldiameter, the use of which would be unacceptable, if the plunger was notstabilized against lateral deflection.

FIGS. 6 through 13 disclose a modified form of the invention, whereinbuildings, such as the building designated generally at 31, has anelevator shaft 32 therein, with an elevator car 34, which car has guideshoes 36 thereon for operation in guided relation on guide rails 38,within elevator shaft 32, by hydraulic cylinder 40 and the plunger 42thereof, so the plunger will lift the car 34 to the desired height or tothe desired floor, such as indicated at 44.

The hydraulic cylinder 40 has a conduit 46 connected thereto and to ahydraulic fluid supply unit 48, such units being well known in the artof hydraulic elevators. The specific controls of the elevator, such asfloor level controls, either automatic or manual, are not shown, as thepresent hydraulic cylinder plunger stabilizer is usable with all formsof controls, as the present device is selfactuating, both as theelevator car moves upward within shaft 32 or as the car moves downwardtherein.

The guide rails 38 are supported in the customary manner within elevatorshaft 32, either by being bolted directly to the masonary wall 50 or tostructural members. such as transverse beams 52 which are mounted onupright structural beams 54. The stabilizing mechanism, for this form ofthe invention, includes stabilizer arms, which are designated generallyat 56, and the latch mechanism, designated generally at 58, which aremounted on structural members, such as the upright beams 54, at spacedintervals throughout the length of the elevator shaft 32, so as tosupport the plunger 42 of the hydraulic cylinder 40, against lateraldeflection, as the car moves upward in guided relation on guide rails38, within the elevator shaft 32. The safe working limit of a plunger ofhigh slendemess ratio is that at which the plunger would not deflectlaterally, therefore, the greatest extended length of the presentplunger, between the lateral supports, will be within the safe workinglimits, therefore, as the elevator car moves upward, the arms 56, whichare pivotally mounted on apertured support members 60 pivotally movefrom the position shown in the upper portion of FIG. 6 to the positionshown in the lower portion of FIG. 6.

Each of the arms 56 is composed of a pair of outwardly extending,apertured members, which member are pivotally mounted on the respectiveshafts 61, on opposite sides of the elevator shaft 32. Each shaft 61extends through the apertures of the respective pairs of arms 56 andthrough the respective apertured support members 60. A transverse bracemember extends between the members of the respective arms 56, and issecured thereto, which braces each support a pair of apertured lugs 64,on the upper side of each arm 56, FIG. 10. A shaft 66 on each of thearms passes through the apertured lugs 64 and through the respectiverollers 68, each of which rollers is in aligned relation with therespective trackways 70 on opposite sides of the car 34, which permitsthe rollers to roll along the trackways as the car moves upward and asthe car moves downward. Each trackway 70 has a curved lower end 72 topermit the rollers 68 to move off the lower end of car 34, as the carmoves upward.

The roller 73 of the respective latch mechanisms 58, as shown in fulloutline in FIG. 11, will be engaged by the respective pivoted, apertureddogs 74, as shown in FIG. 11, each of which dogs are pivotally mountedon the respective shafts 76. The shafts 76 are each mounted on pairs ofapertured lugs 78, which lugs are secured on each side of the car 34. Asthe car moves upward, the upper end of each dog 74 moves, which engagesthe rollers 73 to move the respective arms of latch mechanisms 58 aboutthe axis of shaft 80, which shaft passes therethrough and throughapertured lugs 82, which are mounted on upright beams 54.

The latch mechanisms 58 are moved against tension of springs 84, whichsprings are biased between one of the latch mechanisms 58 and one of theapertured support members 60 on each side of the car 34, until the latchmechanism 58 is in the position shown in dashed outline in FIG. 11,whereupon, the tapered wedge face 86 of the latch mechanism 58 will bemoved upward to disengage wedge face 88 of outwardly extending lever 89.As the rollers 68 move from the longitudinal trackways 70 onto thecurved portion 72 thereof, the respective springs 90, each of which isattached to a lever 92 on each arm 56 and to an outwardly extending lug93 on each of the upright beams 54, which will cause each arm to rotateabout the axis of the respective shafts 61, from the position as shownin full outline in the upper portion of FIG. 6, to the outwardlyextended position as shown in the lower portion of FIG. 6 and in FIGS.8, 9, 10 and 12.

An arcuate yoke 94 is mounted on the end of each arm 56 remote from thepivot shaft 61, and the arcuate curvature of each yoke 94 iscomplementary to the outer diameter of the plunger 42, which plunger isengaged by the yokes 94. The curved portion of each yoke 94 ispreferably lined with an arcuate lining 96. which lining may be leather,rubber, plastic composition, or metal, which will not mar the surface ofthe plunger 42. It is to be pointed out that the upper end of eacharcuate yoke 94 lies in a horizontal plane which is coextensive with theaxis of the respective horizontal shafts 61, or slightly lower, because,as the arms move downward, the upper edge of the lining 96 and arcuateyoke 94 must move arcuately away from the plunger 42, if the arcuateyokes 94 and the linings 96 are to fit in snug relation around theplunger 42. After the elevator car 34 is moved upward, the arms 56,which in the present instance, are shown to be on opposed lateral sidesof the elevator shaft, the plunger 42 will be supported against lateraldeflection, and with these arms being at spaced intervals throughout thelength of the plunger 42, the plunger will be maintained in true axialalignment with the axis of the hydraulic cylinder 40 and with the anchorpoint on the lower side of the car 34.

The present elevator car 34 shows the guide shoes 36 and the guide rails38 located medially between the front and back of the car, and the arms56 and the plunger 42 located forwardly thereof. However, this :ismerely representative, as the cylinder can be located centrally of thecar and the guide shoes 36 and guide rails 38 off-set laterally withrespect thereto, or, the arms can operate on the front and back of theelevator shaft, or, the arms may be disposed on each side of theelevator shaft, with the guide rails 38 and guide shoes 36 being locatednear or at two diagonal corners of the elevator car, if more angulardivergence is desired between the members of the arms 56.

With the plunger 42 stabilized in the manner set out above, a hydraulicelevator may be used for buildings of twelve or more stories, and aplunger of smaller diameter than is customarily used in buildings oflesser height may be used, depending on the load to be carried and thespeed at which it is desired to have the car operate.

The latch mechanisms 58 are each located out of alignment,longitudinally, with the respective trackways 70, and the dogs 74, aswill best be seen in FIG. 9, and are in longitudinal alignment forengagement with the respective rollers 73 on each side of the car 34, asthe car moves upward. The upper ends of the trackways are curvedinwardly, as indicated at 71-71, so as to guide the respective rollers68 onto the respective trackways 70 with the respective rollers 73 ofthe latch mechanisms 58 engaging dogs 74, as the car moves upward,whereupon, as the car passes beyond a certain point, the latchmechanisms will move :arcuately about the respective shafts until therollers 73 and dogs 74 will be disengaged, whereupon, the latchmechanisms 58 will move into the position as shown in full outline inFIG 12, with a leg 59, secured to the bottom of each latch mechanism 58,the leg will come to rest on the respective plates 63, which are securedto one of the support members 60 on each side of the elevator shaft, aswill best be seen in FIGS. 10, 11 and 12, and the springs 84 will holdthe latch machanisms 58 in outwardly extended positions ready to engagethe wedge face 88 of each lever 89, when the car 34 moves downward, aswill be more fully described hereinafter.

When the car 34 has reached the upper-most point of the travel thereof,and it is desired to reverse the travel, the hydraulic fluid isexhausted from the cylinder 40 in a conventional manner, to allow thecar to move downward. As the car moves downward, the lower angulatedface of the dog 74, on each side of the car 34, will move into contactwith the periphery of the respective rollers 73, which will cause therespective dogs 74 to move inward against the tension of the respectivetorsion springs 75, which springs are biased between each of the dogs 74and one of the lugs 78, with the dogs 74 yielding inwardly, as indicatedin FIG. 7, and since the rollers 68 have engaged the curved portion 72on the lower side of car 34, the rollers 68 will move onto the trackways70, which are parallel to the line of travel. As this movement takesplace, the angulated face of each lever 89 will engage the respectiveangulated faces 87 on the lower side of each of the latch mechanisms 58,and upon the arms swinging through an are from the position shown inFIG. 8 to the position shown in FIG. 7, the levers 89 will move latchmechanisms 58 upward about shafts 80 until the wedge face 88 willwedgingly engage with wedge face 86 on each latch mechanism 58, with thesprings 84 holding the latch mechanisms in the position shown in fulloutline in FIGS. 7 and 11, the car 34 will move downward to cause thedogs 74 to engage successive pairs of rollers 73 on the latch mechanisms58, which dogs will yieldingly pass the rollers 73 of the latchmechanisms 58, with the springs 84 maintaining the latch mechanisms 58engaged with the levers 89. Each time the dogs 74 disengage rollers 73,as the car moves downward, the dogs 74 will be returned to the positionshown in FIGS. 11 and 13, and the face 98 thereon will seat against anabutment, such as the face of the car, to maintain the dogs 74 at anangle, as shown in FIGS. 11 and 13, so the dogs will engage the rollers73 upon upward movement of the car 34, which dogs will yield as the car34 passes downward thereby.

As the car 34 moves downward, the rollers 68 move ofi the arcuate upperend of each trackway 70, as shown in the upper portion of FIG. 6, andupon the car 34 returning to the lowermost point of travel, all the armsare held in retracted position, substantially as shown in the upperportion of FIG. 6, and in FIG. 7.

Having thus clearly shown and described the invention, what is claimedas new and desired to be secured by Letters Patent, is:

1. A stabilizer for fluid cylinder plunger in combination;

(a) an outer stationary structure,

(b) an inner movable portion arranged for sliding movement within saidouter stationary structure,

() a hydraulic cylinder mounted in fixed relation with respect to saidouter stationary structure,

(d) an elongated hydraulic cylinder plunger operatively fitted withinsaid hydraulic cylinder for move ment relative thereto andinterconnecting the outer stationary structure and the inner movableportion,

(e) a pair of complementary, movable arms pivotally mounted onhorizontal axes on said outer stationary structure and adapted to extendlaterally thereinto to engage said hydraulic cylinder plunger, when inone position, and to move out of engagement with said hydraulic cylinderplunger when in another position.

(f) arm actuating means, which are springs biased between the respectivearms and the outer stationary structure, associated with said outerstationary structure to urge said pair of complementary arms intoengagement with said hydraulic cylinder plunger upon movement of saidinner movable portion thereabove in said outer stationary structure,

(g) said inner movable portion has a pair of trackways thereon, whichare in aligned relation with the longitudinal movement of said innermovable portion,

(h) each said trackway having a curved portion near the lower end ofsaid inner movable portion, each which curved portion forms a cam,

(i) a cam engaging member mounted on a side of each said arm and beingengageable with said cams and said trackways on said inner movableportion, when said inner movable portion is moved downwardly to movesaid arms out of engagement with said plunger and out of the path ofsaid inner movable portion, and being adapted to disengage saidtrackways and said cams on said inner movable portion, when said innermovable portion is moved upwardly, so said arms will extend laterallyinward to engage said plunger.

2. A stabilizer for a hydraulic cylinder plunger, as

defined in claim 1; wherein (a) said cam engaging member, mounted on aside of each arm, is roller means.

3. A stabilizer for a hydraulic cylinder plunger, .15

defined in claim 1; wherein (a) said arm actuating means includes anoutwardly extending lever secured to each arm and being coordinated tomove therewith, and

(b) said springs, which are biased between the respective arms and theouter stationary structure, have one end of each spring connected toeach said lever.

4. A stabilizer for a fluid cylinder plunger for an elevator or thelike, which stabilizer comprises in combination:

(a) an outer stationary structure,

(1) said outer stationary structure having an eievator shaft formedtherein for a portion of the height thereof,

(b) an elevator car movably mounted within the elevator shaft for guidedmovement longitudinally therein,

(c) a hydraulic cylinder mounted in fixed relation with respect to saidouter stationary structure,

(d) an elongated plunger operatively fitted within said hydrauliccylinder for movement relative thereto, and having the end of saidplunger remote from said cylinder connected to said elevator car,

(e) horizontal shafts mounted on said outer stationary structure,

(f) a pair of complementary, movable arms, one mounted on each saidhorizontal shaft for rotation about the respective axes thereof tocomplementally engage said hydraulic cylinder plunger when in oneposition, and to move said arms out of engagement with said plunger,when in another position,

(g) arm actuating means, which are springs biased between the respectivearms and the outer stationary structure, which urge said pair ofcomplementary arms into engagement with said plunger upon movement ofsaid elevator car upward in said elevator shaft,

(h) said elevator car has a pair of trackways thereon which are inaligned relation to the longitudinal movement of said car,

(i) each said trackway having a curved portion near the lower end ofsaid car, each which curved portion forms a cam,

(j) a cam engaging member mounted on a side of each said arm and beingengageable with said cams and said trackways on said car, when saidelevator car is moved downwardly to move said arms out of engagementwith said plunger and out of the path or said elevator car, and beingadapted to disengage said trackways and said cams on said car, when saidcar is moved upwardly, so said arms will extend laterally inward toengage said plunger.

5. A stabilizer for a fluid cylinder, as defined in claim 4; wherein (a)a latch means is pivotally mounted on said outer structure,

(b) dog means pivotally mounted on said elevator car.

(1) said latch means being in longitudinal alignment with the path ofsaid pivoted dog means upon movement of said elevator car,

(2) said dog means being adapted to engage said latch means to move saidlatch means out of locking engagement with said arms to permit said armsto swing laterally inward into engagement with said plunger upon upwardmovement of said elevator car, and

(3) said pivoted dog means adapted to yield upon engagement with saidlatch means upon downward movement of said car to permit said arms to bemaintained in locked relation out of the path of said elevator car assaid elevator car moves downward.

6. A stabilizer for a fluid cylinder, as defined in claim 5; wherein (a)each said arm has a lever thereon,

9 10 (1) each said lever having a Wedge-like face tracted position outof the path of said elevator thereon, car. (2) each said latchmechanisms having a comple- References Cited mentary Wedge-like face toengage the Wedge- UNITED STATES PATENTS like face of each sa1d lever,when 1n one position 5 and to release said wedge'like faces when said773,478 10/1904 Conner et a1 187 17 latch mechanisms are in anotherposition, and 827,282 7/1906 AT 1der5n (3) a spring biased between saidlatch mecha- 3,016,992 1/1962 Wllson 52115 nisms and said outerstationary structure to normally urge the Wedge-like face of said leverand 10 HENRY SUTHERLAND P'lmary Exammer' the Wedge-like face of saidlatch mechanism into PRICE C. FAW, Assistant Examiner. Wedging relationto maintain said arms in re-

